Variable escapement for typewriters



June 30,1931. B. M. DES JARDINS- I VARIABLE ESCAPEMENT FOR TYPEWRITERS Filed March 12, 1926 INVENTOR Patented June 30, 1931 PATENT OFFICE BENJAMIN M. DES JARZDINS, OF WEST HARTFORD, CONNECTICUT VAIRIAIBLEVESCAPEMENT FOR TYPEWRITERS Application filed March 12, 1926. Serial No. 94,178.

My invention relates to improvements in variable escapements for typewriters and has for its object to provide means whereby the simultaneous depression of a spacing key and a character key will cause the escapement mechanismto permit a lateral feeding movement of the platen greater than the unit movement permitted by the depression of either a spacing key or a character key. It

is an object of my invention to provide improvements in typewriter escapement mechanism which will speed up the operation of the typewriter by permitting the spacing key to be depressed, to space words, simultaneously with the depressiono-f the'character key for the last letter of the word, such simultaneous depression of the keys resulting in a spacing double the unit space formed by the depression of a spacing key or a character key. A further object of my invention is to provide a combination of elements, accomplishing the foregoing objects, of such a nature that the improvements may be embodied in a standard typewriter, for instance, an Underwood typewriting machine, without changing any of the present parts of the machine.

Further objects, and objects relating to details and economies of. construction and operation, will definitely appear from the detailed description to follow. In one instance I I accomplish the objects of my invention by the devices and means set forth in the following specification. My invention is clearly defined and pointed out in the appended claims. A structure constituting a preferred embodiment of my invention is illustrated in the accompanying drawings, forming a part of this specification, in which:

Figure 1 is a vertical sectional view through a typewriter showing the key action and escapement mechanism embodying my invention; 1 Fig. 2 is a fragmentary View, in rear elevation, ofthe novel pawl carried by the dog rocker and cooperating with the escapement wheel in accordance with my invention, and 'Fig. 3is a fragmentary, perspective view of the cam plate and lever co-acting therewith 5 'to control said pawl.

Fig. 4 is a fragmentary view correspond ing to Fig. 2 but showing the pivoted pawl in position to permit double spacing.

In the drawings, the same reference numerals refer to the same parts throughout the several views.

I have illustrated, in the drawings, parts of a standard Underwood typewriter with other elements added thereto for the purpose of incorporating my invention in such machine. Parts of the pivotal bearings on the frame of this machine are designated by X, and frame or other existing fixed parts by XX. The character keys, 10, (one only being shown) are carried on key levers and so connected to pivoted type bars as to swing the corresponding type 11 against the platen 12 upon the depression ofacharacter key. As the type strikes the platen, the shoulder 13 on the type bar strikes the universal bar 14 and ushes the universal bar plate 31 rearwar ly causing the rear end 16 thereof to rock the dog rocker 15 on its pivot. The dog rocker ooacts with the escapement wheel 17 and, by this action of the escapement mechanism, the platen 12 is fed laterally a unit space for each depression of a character key. The lever 18 carrying the spacing key 18XX, in the standard Underwood typewriter, is

located under the rocker 19, so that depression of the spacing key rocks lever 18 and rocker 19, and thereby operates the dog rocker 15 and escapement mechanism to feed the platen laterally a unit distance. These parts are of well-known form and action.

To embody my invention in this standard machine, I have substituted, for the dog rocker customarily used, a rocker 15 of somewhat difierent form pivotally mounted as before and having a forwardly-extending arm 27 and a laterally-extending finger 28. The location of the spacing lever 18 is changed, so that its rear end is no longer under rocker 19. An arm 20 is pivoted on the ribbon feed rod 21X and carries a lateral stud 22 supporting the lower end of a cam plate 23 above the rear end of lever 18, so that depression of the spacing key will raise cam plate 23. The upper end of the cam plate is normally pulled forwardly by a light offset therefrom, and provided with a secondtooth 41. These teeth coact with the merit wheel 17.

The stop lever 34 is pivoted on rod 35 and its rear arm 37 has a lateral extension en gaging arm 39 of pawl 88. The forward arm of lever 34 has a lateral extension 36 located in the path of plate 23 and the latter is provided with a cam surface 29 co-acting with the beveled or curved surface of exten-, sion 36. A plate 32 is fastened to theuni: versal bar plate 31 and has a cam surface 33 co-operating with a cam surface 30 formed on the upper end of cam plate 23.

The operation of this mechanism embodying my invention is as follows. Normally, the teeth of pawl 38 are in mesh with escapement wheel 17 and the tooth of dog rocker15 is out of mesh. The carriage spring tending to turn wheel 17, acting on pawl 38, holds it against the stop 40a provided on the dog rocker. If a character key is depressed, singly, the type bar moves the universal bar rearwardly, rocking the dog rocker 15 and moving the rocker tooth into mesh with wheel 17 and the pawl teeth out of mesh. Thereupon, thespring attached to pawl 38 swings it in a'clockwise direction (Fig. 2) until its lower arm 39 hits the stop lever 34. -Upon the release of the character key, the rocker swings back and tooth 42 on pawl 38 engages the escapement wheel once more, one step. in advance of its previous position, thus permitting the vplaten to have alateral movement of one unit space. If the spacing key 13XX is depressed, singly,the cam plate 23 israised and its shoulder 26, engaging fingerf 28,

- swings the rocker 15 to unmesh the pawl teeth and mesh the rocker tooth. Upon the release of the spacing key, the rocker swings back and the platen feeds one unit space, just as upon t 1e depression of a character keyi If, however, a character key and the spacing key are depressed simultaneously, the rearward movement of the universal bar brings cam surface33 into the path of cam surface 30 on plate 23 and, as that plate is raisedby the de-.

pression of the spacing key, the twocam surfaces coact to swing the upper end of plate 23 rearwardly, against the pull ofspring'24. This causes cam surface 29 to engage the extension 36 and rock stop lever 34 clockwise,

' withdrawing extension 4O from engagement with pawl 38., The spring shown attached to iv the pawl thereupon rocks it against stop 43,

carrying tooth 42 out of operative position and bringing tooth 41 into operative relation to the escapement wheel. The tooth 41 is so located that it will permit a movement of the escapement wheel, when the dog rocker swings back to normal position, such as to permit a lateral feeding movement of the platen of two unit spaces. V

It will be seen that, by the use of my invention, a standard typewriter can cheaply and easily be so changed as to" permit the word spacing to be accomplished simultaneously with the printing of the last letter of a word.

This speeds up the operation since the time needed for the operation of the spacing key, in the practice now usual, is eliminat'ed'and this amounts to a considerablesaving of time inthe operation of the typewriter. I am aware that the mechanismillustratcd and described herein may be changed consid' erably without departing from the-spirit of my invention, and, therefore, I claim my in vention broadly, as indicated by the: ap pended claims. 7 1 What I claim is as follows:

. 1. In a machine of the eharacter'described, the combination of a carriage, an escapement mechanism. therefor, a plurality of character keys, means including an escapement'operating member for causing said escapement mechanism to feed the carriage. a unit distance upon the operation of any character key, aspacing key, connections whereby the operation of said spacing key causesv the escapement mechanism to feed the carriage a unit distance, a cam on said escapement-operating member, a" second cam on the spacing key connections, said cams having free paths of travel when the spacing key or a character key is separately operated, one of said cams coacting with the other to displace it when the spacing key and a character key are simultaneously operated, and means whereby said displacement shall cause said escapement mechanism to feed the carriage more than a unit distance. '3

2;.-In a machine of the character described, the combination of a carriage, an escapement mechanism therefor, a plurality of charmter keys, a member actuated'by the operation of any character key to cause said escape:- Inent mechanism to feed the carriage a unit distance, said member having a first operating surface, a spacing key, connections where byvtheoperation of said spacingkey will cause the escapement mechanism to feed the carriage a unit distance, said connections .including an element having a second operating surface, engaging and reacting with thefirst operating surface to effect the displacementof said element when the spacing key and. a character key are simultaneously operated, and a third operating surface, and an escapement-controlling stop member'having'a fourth operating surface normally out of engagement with said third surface but engageable thereby upon the displacement of said element to actuate the escapement controlling stop member and permit the escapement mechanism to feed the carriage more than a unit distance.

3. The combination of a carriage, an escapement mechanism for controlling the feed thereof, and including a dog rocker, a plurality of character keys, an escapement-operating bar actuated by the operation of any character key to rock said dog-rocker, a spacing key, a cam plate lifted by the operation of the spacing key to rock said dog-rocker, a projection on the escapementoperating bar normally out of the path of said cam plate but engageable by the. latter to deflect it when the spacing key and a character key are simultaneously operated, a dog forming part of the escapement mechanism, and a stop member normally limiting the movement of the dog to cause the escapement mechanism to feed the carriage a unit distance, but movable out of the path of said dog by the deflection of said plate, whereby the escapement mechanism feeds the carriage more than a unit distance.

4. In a machine of the kind described, the combination with space and character keys, an escapement Wheel and a rocker having a rigid pawl cooperating therewith, of a pawl pivoted on said rocker and having a tooth normally coacting with said wheel to limit the movement thereof, a stop limiting the movement of said pivoted pawl under pressure exerted thereon by the escapement wheel, said pivoted pawl having a tail extending from said tooth in a plane offset therefrom and a second tooth on said tail extending laterally into the plane of the first tooth, and means, actuated by the simultaneous depression of space and character keys, for controlling the swinging of said pawl to carry the first tooth out of and bring the second tooth into operative relationship with the escapement wheel.

5. In a machine of the kind described, the combination with escapement mechanism, space and character keys, means whereby the operation of any space or character key will actuate the escapement mechanism a unit distance, and means including coacting cams, brought into cooperation by the simultaneous depression of space and character keys, to actuate the escapement mechanism a distance greater than unit distance.

, In testimony whereof I have affixed my signature.

BENJAMIN M. DES JARDINS. 

